(WRAS) State Water Plan Subbasin 20F Chartiers Creek Watershed (Ohio River) Washington and Allegheny Counties

Updated 9/2003 Watershed Restoration Action Strategy (WRAS) State Water Plan Subbasin 20F Chartiers Creek Watershed (Ohio River) Washington and Allegheny Counties Introduction Subbasin 20F includes the 296-square mile Chartiers Creek watershed located in southwestern Allegheny and northern Washington Counties and the 19.4 square mile watershed of Sawmill Run, the upstream most named tributary flowing directly into the Ohio River. A total of 408 streams flow for 567 miles through the subbasin. Most of the tributary watersheds are small; only Little Chartiers Creek and Robinson Run have drainage areas greater than 30 square miles. Chartiers Creek starts in a rural section of northern Washington County and flows north through Allegheny County and the western Pittsburgh suburbs and through the Pittsburgh City limits to its confluence with the Ohio River near McKees Rocks. The subbasin is part of HUC Area 5030001, Upper Ohio River, a Category I, FY99/2000 Priority watershed in the Unified Watershed Assessment. Geology/Soils: The entire subbasin is in the Western Allegheny Plateau Ecoregion. The upper third of the subbasin is in the Permian Hills (70a) subsection and the lower portion is in the Monongahela Transition Zone (70b) subsection. Strata are composed of sequences of sandstone, shale, limestone, and coal. The commercially valuable Pittsburgh coal underlies the entire subbasin. The upper basin was extensively deep mined starting in the late 1800’s, by the room and pillar method, with coal left in place to support the overlying rock and surface. The region supplied coal and coke for the numerous steel plants in the Pittsburgh region. More recent mines are far beneath the surface and employ the newer technique called longwall mining, in which huge blocks are removed, with the overlying rock collapsing soon after the coal is removed. The second most valuable coal is the Waynesburg coal, which is surface mined in the upper basin in Washington County. Significant extraction of the Upper Freeport coal also occurred. Oil and gas reserves were also located in the subbasin. Washington County was once a large producer of oil in Pennsylvania. Oil production has declined to secondary production in established fields. Soils in this basin are derived from noncarbonate sedimentary rocks. The infiltration rates are moderate, which allows for good hydrologic characteristics. The hilly terrain has shallow well-drained soils. Land Use: Chartiers Creek watershed has a combination of urban, rural, forested, agricultural and surface mined land uses. The major urban areas are the city of Pittsburgh and its suburbs at lower Chartiers and Little Chartiers Creek, Cannonsburg at mid Chartiers Creek and Washington near the upper end of Chartiers Creek. This area was an important steel, railroad and manufacturing hub up to the early 1900’s. I-79 and I-70 pass through the subbasin. A suburban/urban corridor is adjacent to I-79 from Washington PA to Pittsburgh. Around 350,000 people lived within the subbasin as of the 1990 census; the population is projected to increase significantly to 520,000 by the year 2040. Natural/Recreational Resources: Upper St Clair Township is completing a master plan for their 474-acre Boyce/Mayview Park, which is listed in the Allegheny County Natural Diversity Inventory as a significant biological diversity area. The 76-acre PA Fish and Boat Commission (PFBC) owned Canonsburg Lake is located in the 1 Washington County portion of the watershed. A field survey by the PFBC in May 2000 indicated that the lake contains an excellent population of largemouth bass. A good population of large channel catfish is also present. Chapter 93 designated Exceptional Value (EV) and High Quality Streams (HQ): EV: None. (HQ): • Reservoirs #2, 3 and 4 on upper Chartiers Creek • Little Chartiers Creek, from headwaters down to Alco Dam • Little Sewickley Creek Water Quality Impairment The subbasin suffers from a variety of nonpoint and point source pollution sources. New and expanded municipal sewage treatment plants have resulted in water quality improvements over the past 20 years; however combined storm sewer overflows still carry considerable urban runoff into the streams. Habitat and stream channel modification g from urban development and impervious cover are also significant causes of impairment in the lower portion of the watershed. Portions of the watershed are also affected by agricultural activities and abandoned mine drainage (AMD). AMD impairment is most apparent in the lower half of the watershed. Coal pillars left as support during underground mining allow pyretic material to come in contact with water in the flooded mines; water leaving the mines carries large loads of iron. Most of the mine discharges were acidic soon after they were flooded; however, many have become highly alkaline from contact with calcareous material in the overburden. The deep mines now discharge heavily iron-laden water to the receiving streams. These alkaline discharges are starting to be treated passively with constructed wetlands to remove the iron. Some of the active underground mines that are mining the extremely deep Pittsburgh coal in the Washington County portion of the subbasin have intercepted brines and discharge water that is highly alkaline with very high concentrations of total dissolved solids (TDS), sodium, chloride, calcium and sulfate. Some of these mines use longwall mining methods which can result in extensive areas of subsidence soon after mining. This subsidence can affect stream flow, highways and other surface structures. Monitoring/Evaluation The DEP Southwest Regional Office inventoried subbasin 20F through the unassessed waters program in 1997. They reaffirmed the earlier 303d listings and added many additional stream segments to the list. The subbasin is has one of the highest percentages of impaired miles in Pennsylvania. A total of 461 stream miles or 84% of the subbasin are listed as impaired on DEP’s 2000 303d list. Only 87 assessed miles were determined to be attaining their water quality uses. Impairment sources were abandoned mine drainage, surface and subsurface mining, habitat modification, on-site wastewater, urban runoff/storm sewers, construction, and agriculture. In addition to nonpoint sources, 303d listings included fish consumption advisories for 30.37 miles of Chartiers Creek and 0.7 miles of Little Chartiers Creek for PCB and chlordane. The only assessed segments that were considered unimpaired are 49.73 miles of Little Chartiers Creek watershed and 37.46 miles of Robinson Run watershed. Discharges from oil and gas well production and storage and disposal of brines has also resulted in degraded surface and groundwater in some areas. DEP biologists use a combination of habitat and biological assessments as the primary mechanism to evaluate Pennsylvania streams under the Unassessed Waters Program. This method requires selecting stream sites that would reflect impacts from surrounding land uses that are representative of the stream segment being assessed. The biologist selects as many sites as necessary to establish an accurate assessment for a stream segment. The length of the stream segment assessed can vary between sites. 2 Several factors are used to determine site location and how long a segment can be, including distinct changes in stream characteristics, surface geology, riparian land use, and the pollutant causing impairment. Habitat surveys and a biological assessment are conducted at each site. Biological surveys include kick screen sampling of called benthic macroinvertebrates, which are identified to family in the field, and an evaluation of their tolerances to pollution. Benthic macroinvertebrates are the organisms, mainly aquatic insects, that live on the stream bottom. Since they are short-lived (most have a one-year life cycle) and relatively immobile, they reflect the chemical and physical characteristics of a stream and chronic pollution sources or stresses. Habitat assessments evaluate how deeply the stream substrate is embedded, degree of streambank erosion, condition of riparian vegetation, and amount of sedimentation. Future threats to water quality With the large projected increase in population for the basin, urbanization will to be a continued threat to water quality. Degradation from abandoned mines should decrease as passive treatment is used to treat discharges. Water quality should also improve with the expanded schedule of orphan oil and gas well plugging contracted by the Department’s Bureau of Oil and Gas Management. Restoration Initiatives Pennsylvania Growing Greener Grants: • $79,558.89 (FY2003) to Chartiers Nature Conservancy - to develop a restoration plan for mine discharges in the Lower Chartiers Creek Watershed • $35,000 (FY2002) to Mt Lebanon Nature Conservancy for education and outreach in Lower Chartiers Creek watershed. • $15,000 (FY2001) to Green Tree Borough for restoration of Whiskey Run streambanks. • $44,000 (FY2001) to the Chartiers Nature Conservancy for evaluation of discharges from abandoned coal mines in the Lower Chartiers Creek watershed. • $50,000 (FY2001) to Bridgeville Borough for implementation of phase II of the McLaughlin Run restoration project. • $86,872 (FY2000) to Bridgeville Borough for restoration of 1765 feet of streambank along the Bridgeville Borough portion of McLaughlin Run using the findings in Upper St. Claire's 319 funded fluvial geomorphology assessment. • $7,000 (FY2000) to the Chartiers Nature Conservancy, Inc. to provide for enhancing

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